Discard corncobs, herb sprigs, and bay leaf. Cool soup slightly. Working in batches, puree soup in blender until very smooth. Strain into large bowl, pressing on solids to extract as much liquid as possible. Season soup to taste with salt and white pepper. DO AHEAD: Can be made 1 day ahead. Cover and chill.

For garnish:
Cook bacon in small skillet over medium heat until crisp. Using slotted spoon, transfer to paper towels to drain. Transfer to small bowl. Mix in corn, green onion, and pinch of cayenne. DO AHEAD: Can be made 2 hours ahead. Let stand at room temperature.